Locking and clamping means for core barrels



f Patented May 29, 1934 UNITED STATES PATENT OFFICE LOCKING AND CLAMPING' MEANS FOR com: BARRELS Peter J. Duffy, Houston, Tex. Application February 15, 1932, Serial No. 592,883

I 4 Claims. (01. 255-72) The invention relates to an improvement in core barrels of the type which are adapted to be lowered into the drill stem and drill bit during the drilling operation and which may be then removed from the drill bit in order to obtain the core without withdrawing the drill bit from the well bore.

One of the objects of the invention is to provide a core barrel which may be lowered into the drill bit and locked in position to maintain a seal about the core barrel so that the core will not be contaminated by drilling fluid.

Another object of the invention is to provide a core barrel having a plurality of ribs which will center the core barrel with respect to the drill,bit to=assist in maintaining a seal between the drill bit and the core barrel.

Another object of the invention is to provide a locking or latching mechanism for the core barrel which will engage the drill stem in order to lock the barrel in its lowermost position.

Another object of the invention is to provide a latching mechanism for the core barrel which may readily be released in order to remove the core barrel from its core-catching position. Still another object of the invention is to provide a tapered portion on the core barrel which.

will seat upon a similar section of the drill bit.

Another object of the invention is to provide a closed upper end for the core barrel which will prevent the entrance of drilling mud but which will permit the escape of the air entrapped in the core barrel at the time it is positioned in the drill bit.

Another object of the inventionis to provide a releasing mechanism for the core barrel latch which may be released by engagement with a suitable hook which can be lowered into the well bore independently of the core barrel. The invention will be best understood by hav ing reference to the drawing wherein Fig. 1 is a broken vertical section of a drill stem and drill bit in which the corebarrel is positioned.

Fig. 2 is a section looking down on the top of Fig. 1.

Fig. 3 is a section taken on theline 3-3 of Fig. 1 and looking in the direction of the arrows.

Fig. 4 is an elevation, with the ends broken away, of the core barrel illustrating the center ribs and the tapered sealing portion.

It is desirable to obtain a 'core of the strata which is being drilled and with this in mind various types 01! core bits and core barrels have been devised heretofore. The present invention, however, relates to a core barrel ,which may be releaswardly in the well bore outside of the drill stem 4. When it is desired to obtain a core of the formation being drilled a core barrel 5 is positionedin the drill bit. The construction of the core barrel is best seen in Fig. 4, which includes the stem 6, the sealing portion 7, and the body 8.

' The stem 6 is of a diameter to fit smoothly within the opening 9 provided in the drill bit and it is intended that the core barrel will be lowered into the bit so that the stem will pass into the opening 9 in any manner preferred by the operator.

The upper portion of the opening 9 is provided with a plurality of radial slots or grooves 12 which are best seen in section in Fig. 3 and are arranged to receive the ribs 13, which are formed on the stem 6 of the core barrel. These ribs 13 -are shown in section in Fig. 1. Directly above the ribs 13 is the tapered section '7, which isadapted to maintain a seal with the tapered seat 15', which is formed in the' uppermost part of the opening 9 in the shank 16 of the drill bit. It is intended that when the core barrel is properly seated in.

the drill bit that the tapered portion 7 will fit tightly in the seat 15 and prevent any of the drilling mud from the drill stem entering theopening 9 around the core barrel. As is well un- .derstood, the lower portion of the stem 6 may be is attached to the lower portion of the core barrel by means of the threads 18. Thus it is possible to make the body 8 of any desired length depending upon theformation being drilled and the length of the core which it is desired to obtain at a single setting of the core barrel.

While the seat 15 is shown as a metalto metal contact with the core barrel it is intended that the metal may be soft to insure a complete seal or that a special ring or collar of packing material may be provided.

The ribs 13 tend to center the core barrel and insure its proper positioning in the drill bit at the sametime the seal is being maintained.

In order to latch the core barrel in proper position a latching mechanism has been provided adjacent the top of the body 8 and'it is intended that this latching mechanism will be positioned on the uppermost section of pipe which constitutes the body 8. This latching mechanism is mounted upon a cap ,or plug 20, which serves as a closure for the uppermost section 21 of the core barrel. This plug is provided with a valve 22, which prevents the entrance of fluid into the core barrel from the top but allows the escape of fluids from the inside of the core barrel when sufiioient pressure accumulates to overcome the pressure on the top of the core barrel and to raise the .valve member.

Mounted on this cap or plug 20 are a plurality of upstanding brackets23, which are arranged in pairs, as best seen in Fig. 2. These brackets serve .as a support for the flexible element 24, which serves to connect the latching arms 25 and 26 so that when the core barrel is properly seated they will automatically drop in position and latch the core barrel in. the drill pipe. The flexible elements 24 pass through the cross members 30 between the brackets and are suitably supported in this manner. The lower latch arms 26 may be -omitted if desired:

It,is intended that the elements 24willbe of sufiicient length to allow the latching arms 25 and 26 to assume substantially the position shown in Fig. 1 but will not permit them to pass below the center line of the pivot points on which they are mounted.

When it is desired to remove the core barrel it is only necessary tov lower a suitable hook or grab tool which will engage the flexible elements at the'point 32 intermediate the brackets 23 and a pull may then be exerted upon the chain or element 24. This pull will be transmitted to the arms 25 and 26 and raise them to the dotted line position shown in Fig. 1. This tends to release the core barrehand a continued pull will withdraw it from the drill bit and raise it to the surface. It is intended that suitable core catchers of any well known type can be used in the lower position of the core barrel in order to retain the core within the barrel while it is being removed from the well.

As best seen in Fig. 2, two opposite sets of latching arms have been provided so that the core barrel will be properly centered in the drill stem and the opposite latching arms will create a direct thrust against each other to maintain the core barrel in proper position.

While one specific form of latching mechanism has been shown and described it is contemplated that this may be varied within the scope of the appended claims as desired.

The present application is substantially a duplicate of my prior copending application, Serial #423,164, filed January 24, 1930.

Having described the invention, what I claim as new is:

1. The combination of a core bit and core barrel including a plurality of grooves in said bit, a plurality of ribs on said barrel adapted to-interfit with said grooves to center said barrel in said bit, means including friction shoes to hold said barrel in said bit in core-catching position, and additional means including a tapered seat to form a seal betweensaid bit and said barrel.-

2. A core barrel of the character described including-a stem, ribs on said stem adapted to seat in-the drill bit to center the core barrel, a sealing portion on said core barrel to engage the drill bit, and means carried by said core barrel to releasably engage the drill stem including a plurality of pivoted friction shoes to. hold said core barrel in core-cutting position.

3. In combination with a core barrel or pipe a plug removably threaded into'one end thereof, a valvular air controlled passage in said plug, a plurality of brackets carried by said plug in axial alignment with the plug, said brackets having holes at their upper ends, a series of radial curved arms having their inner ends pivoted upon the brackets, segmental dogs formed terminally upon the arms, a plurality of chains secured each at one end upon one arm and having its opposite end movably projecting through a hole of the bracket, anda hand hold connected to the free ends of all of the chains by means of which the chains may simultaneously be operated to open or close the arms to place the dogs in and out oi gripping position.

4. As a new article of manufacture an anchoring device for a core barrel or pipe consisting of a screw plug having a central through passage arranged axially therein, a check valve controlling the passage, a series of outwardly projecting brackets fixed thereupon, having holes at their upper ends, pivot pins carriedby said brackets at their lower ends, a series of arms, each having an inner curved terminal mounted upon one of said pivots, a dog carried by each arm at its outer end, a series of chains or rods projecting through 

